The present invention relates to a method for repairing bicycle tubular tires, notably of the tubeless type.
It is known that bicycle tubular tires are tires in which a lightweight tube is enclosed in a bias-fabric tires cover consisting of a carcass and a tread. The carcass may be closed in various ways:
by stitching with a sewing machine capable of making different types of stitches;
by using a zip fastener;
by cementing the two edges of the cover during the moulding operation.
While the use of a zip fastener, proposed many years ago but not used commercially for closing tubular tires, may prove extremely convenient for repairing a punctured tires, this is not so for the stitched tires and still less for the cemented closing which cannot admit of any kind of repair.
In the case of a stitched tubular tire, the repair is performed by firstly detaching a protection tape applied over the seam in the punctured area, then cutting the seam threads along a length sufficient to permit the removal from the tire of the inner tube portion which was punctured, and eventually applying a rubber puncture-patch on the hole. Then, after re-inserting the inner tube, the operator must stitch the seam manually along the previously removed portion. This is done by making cross-stitches or herringbone-stitches, and the needle and thread must pass through the holes of the previously cut seam. In addition, the thread must be tightened in such a way that upon completion of the repair operation and refitting the protection tape no throttling nor expansion of the tire remains visible when the latter is refitted on the rim and inflated.
From the foregoing it is clear that all these repair operations are tedious and time-consuming. Except for some retired people and former cycle racers, nowadays nobody is willing to do the job and cyclists must repair their tubular tires themselves.
Of late, various tubeless tubular tires have been proposed commercially (see French Pat. No. 76 10229 filed on Apr. 8, 1976 by the same Applicant), i.e. tubular tires in which the impervious layer retaining the air therein is formed integrally with the cover. As a result, in case of puncture, the hole formed through the tread and the hole formed through the impervious layer remain in mutual alignment, notwithstanding the tire deflation.
To repair this type of tubeless tubular tire the only proposition made up to now consisted in injecting through the valve rubber latex or another emulsion suspension likely to seal the puncture more or less adequately. Considering the random distribution of the product thus injected, this repair method is not always efficient and reliable.